We played with the idea of having a Java version of the DB API, but, frankly, there was never much demand for it.
Also, I am not sure that there is much to gain with having the device data in a RDBMS. In terms of performance, you can hardly beat a API serving device data off-memory.

Can you tell us more about what you are trying to do?

If your problem is simply having the data in the DB in some form, the solution could simply be to store the wurfl.xml in a blob and modify the class that loads the wurfl.xml slightly to read it from there. You have access to the source code and a moderately skilled Java programmer should be able to make this change and plug it in through the Spring Framework.